package unit08;

public class Demo01 {
    public static void main(String args[]) {
        String t1 = "ABCDabcd";
        String s1 = t1.toUpperCase();
        String s2 = t1.toLowerCase();
        System.out.println(s1);
        System.out.println(s2);
        String s3 = s1.concat(s2);
        System.out.println(s3);
    }
}
